POSSUM - Present tense The verb possum, posse, potui -- be able, can is a form of sum with the prefix pos- or pot-. Notice that the prefix pot- is used before vowels, while the prefix pos- is used with consonants. Unscramble the letters to form the Latin word that fits the given definition. Tools This activity was created by a Quia Web subscriber. To learn how to make your own, just like this, click here.